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It’s not reaching it, it’s staying there. The heat and plasma represent enormous challenges. Comms are incredibly difficult to maintain, for example.

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Thank god for the comms problem. Without it, hypersonic missles probably aren't far from being able to take out any aircraft carrier.

That would be bad for Taiwan.

A barrage of regular missiles would easily be able to take out any aircraft carrier. You don’t need hypersonic.

This is due to the simple fact that you can only carry so much AA ammunition and restocking ammunition on a ship takes significantly longer than it does on land.

This isn’t even touching on drones, both flying and boats, as well as torpedos and mines.

Taking out an aircraft carrier isn’t difficult. It’s just that luckily, no country with the capacity to do so has been crazy enough to start ww3.

fwiw european diesel-electric submarines routinely sink supercarriers in exercises

Isn't this the same with any speed, though? We've always had trouble breaking the next record.

The point isn't specifically having trouble breaking the record, the point is that having to deal with the plasma makes it a completely different flight regime with completely different design considerations, exactly like how sustained supersonic flight requires all sorts of considerations that are very different from what subsonic flight requires.

Yes, that's one problem. The GP said there are two problems, the other one being "we can't reach this speed easily".

I think what they mean is: Sonic speeds / Mach 1 brings a set of problems. Mach 2, 3, 4 don't add new ones. But Mach 5 does, hence warranting a different naming with hypersonic. At least that's how I understood the conversation.

I believe the second issue is that engines which work well at supersonic speeds don't work well at slower speeds and visa versa

"A typical air-breathing DMRJ propulsion system can only begin operating when the vehicle achieves supersonic speeds greater than Mach 3. In fact, since ramjet (and scramjet) engines don’t have rotating parts (compressor and turbine) as turbojet and turbofan engines, they rely on specially designed air inlets to compress the air to the pressure required for the combustion.

The efficiency, however, only gets sufficiently high when the speed reaches at least Mach 2, due to the higher temperature and pressure obtained in the combustion chamber. This is why ramjets usually need other means to reach the minimum speed for ignition, such as rocket boosters or, in the SR-71 Blackbird, dual cycle turbo-ramjet engines."

from https://theaviationist.com/2023/12/16/ge-aerospace-demonstra...

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